1. Field of the Invention
The present invention is related to a fan having balancing blade sets for balanced rotation, and more particularly to a fan having a plurality of blade sets in balance with relation to an axis of the fan to ensure stable rotation.
2. Description of the Related Art
A variety of fan blade designs have been employed in cooling electronic devices such as CPUs, and in similar heat exchanger applications. In various applications, fan blades are designed to move airflow through adjacent heat exchangers, a heat sink for example, or through air channels. Balance of rotation is an important consideration in fan operation and high balance level is also a requirement. Therefore, a need exists for improved construction of the fan.
Referring initially to FIG. 1, an axial flow fan 9 consists of a central hub 90, a plurality of fan blades 91 extending radially outward from an outer circumference 92 and a shaft 93 axially extending from the central hub 90. It moves simply and axially airflow by means of rotating blades 91.
Referring to FIG. 2, U.S. Pat. No. 6,179,561 discloses a fan 8 comprising a central hub 80, a plurality of axial blades 81, a plurality of blower blades 82 and a shaft 84. The blades 81 and 82 are extended radially outward from an outer circumference 83 of the central hub 80 and are directly concerned with movement of air. Functionally, the blades 81 and 82 move airflow axially and radially in synchronization while the fan 8 is rotating. Furthermore, the axial blades 81 and blower blades 82 are separated into two stacking layers on the outer circumference 83, one layer for axial blowing and the other layer for radial blowing. However, the recent trend in fan blades has been to incorporate various blade designs into a common layer for both enhancing airflow""s efficiency and reducing the entire thickness of the fan. Meanwhile, balance of rotation when incorporating various blade designs is still an important consideration.
Other fans are designated various blade designs on different layers, see for example U.S. Pat. Nos. 3,904,308 and 4,502,837.
The present invention is intended to provide a plurality of blade sets arranged in balance, each set comprising various blade designs and formed within an appropriately angular length for balanced rotation in such a way as to mitigate and overcome the above problem.
The primary objective of this invention is to provide a fan having balancing blade sets to rotate in balance and ensure stable rotation.
The secondary objective of this invention is to provide a fan having balancing blade sets which comprise various blade designs that enhance blowing efficiency.
The present invention is a fan having balancing blade sets. The fan having balancing blade sets mainly comprises a central hub, a shaft and a plurality of blade sets. The blade sets are radially extended from an outer circumference of the central hub and each blade set is uniformly formed within an appropriate angular length to ensure stable rotation. Each blade set is comprised of various blade designs to enhance blowing efficiency.
Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description and the accompanying drawings.